Adaptable and Secure Can Bus

Abstract

A communication module is configured to communicate a first part of a message packet configured to identify message content contained in the message packet and a second part of the message packet and change the second part of the message packet in response to a trigger. A received message packet's changing portion is compared with the set of the authorized changing portions to determine whether the received message packet is authorized for the common control network. The received message packet is discarded or ignored in response to the received message packet's changing portion not matching at least one of the authorized changing portions in the set of the authorized changing portions.

1 .- 46 . (canceled) 
     
     
         47 . A method of operation for a first communication node communicating on a common control network, the method comprising:
 communicating from a communication port of the first communication node onto the common control network a first part of a message packet configured to identify message content contained in the message packet and a second part of the message packet;   changing the second part of the message packet in response to a trigger;   storing in a memory associated with the first communication node a set of authorized changing portions of message packets associated with communication nodes on the common control network;   changing the authorized changing portions of the message packets associated with the communication nodes on the common control network;   comparing a received message packet's changing portion with the set of the authorized changing portions to determine whether the received message packet is authorized for the common control network;   discarding or ignoring the received message packet in response to the received message packet's changing portion not matching at least one of the authorized changing portions in the set of the authorized changing portions.   
     
     
         48 . The method of  claim 47  further comprising, in response to receiving the received message packet's changing portion not matching at least one of the authorized changing portions in the set of the authorized changing portions, sending an alert message on the common control network configured to cause a change in status of the communication nodes on the common control network. 
     
     
         49 . The method of  claim 48  further comprising, in response to receiving an alert message from one of the communication nodes on the common control network, changing the second part of the message packet sent from the communication port. 
     
     
         50 . The method of  claim 49  further comprising, in response to receiving a message from one of the communication nodes on the common control network, waiting for a given time before sending a message, the given time sufficient to allow for detection of an unauthorized message and receipt of the alert message. 
     
     
         51 . The method of  claim 47  further comprising changing the second part of the message packet in response to one of the group consisting of:
 passage of a given time period, receipt of a given number of received messages, sending of a given number of sent messages, receipt of an alert message at the communication port, combinations thereof. 
 
     
     
         52 . The method of  claim 47  further comprising changing the second part of the message packet by switching to a different value in a lookup table. 
     
     
         53 . The method of  claim 47  further comprising communicating from the communication port a third part of the message packet configured to change and to change the third part of the message packet using an algorithm different from an algorithm used to change the second part of the message packet. 
     
     
         54 . The method of  claim 53  further comprising sending the message packet with the third part using an algorithm different from the second part of the message packet in response to a state of a systems for the common control network being in a sensitive state. 
     
     
         55 . (canceled) 
     
     
         56 . The method of  claim 47  wherein the first part is scattered over at least a portion of the second part of the message packet. 
     
     
         57 . The method of  claim 47  further comprising communicating from the communication port a third portion of the message packet that includes semi dynamic bits. 
     
     
         58 . The method of  claim 57  wherein the semi dynamic bits are scattered over at least a portion of the second part of the message packet. 
     
     
         59 . A communication node apparatus comprising a communication port comprising a processing device, wherein the communication port is configured to:
 effect communication from the communication node apparatus onto a common control network a first part of a message packet configured to identify message content contained in the message packet and a second part of the message packet;   change the second part of the message packet in response to a trigger;   store in a memory associated with the first communication node a set of authorized changing portions of message packets associated with communication nodes on the common control network;   change the authorized changing portions of the message packets associated with the communication nodes on the common control network;   compare a received message packet's changing portion with the set of the authorized changing portions to determine whether the received message packet is authorized for the common control network;   discard or ignore the received message packet in response to the received message packet's changing portion not matching at least one of the authorized changing portions in the set of the authorized changing portions.   
     
     
         60 . The communication node apparatus of  claim 59  further comprising, in response to receiving the received message packet's changing portion not matching at least one of the authorized changing portions in the set of the authorized changing portions, sending an alert message on the common control network configured to cause a change in status of the communication nodes on the common control network. 
     
     
         61 . The communication node apparatus of  claim 60  wherein the communication port is further configured to, in response to receiving an alert message from one of the communication nodes on the common control network, change the second part of the message packet sent from the communication port. 
     
     
         62 . The communication node apparatus of  claim 61  wherein the communication port is further configured to, in response to receiving a message from one of the communication nodes on the common control network, wait for a given time before sending a message, the given time sufficient to allow for detection of an unauthorized message and receipt of the alert message. 
     
     
         63 . The communication node apparatus of  claim 59  wherein the communication port is further configured to change the second part of the message packet in response to one of the group consisting of: passage of a given time period, receipt of a given number of received messages, sending of a given number of sent messages, receipt of an alert message at the communication port, combinations thereof. 
     
     
         64 . The communication node apparatus of  claim 59  wherein the communication port is further configured to change the second part of the message packet by switching to a different value in a lookup table. 
     
     
         65 . The communication node apparatus of  claim 59  wherein the communication port is further configured to communicate a third part of the message packet configured to change and to change the third part of the message packet using an algorithm different from an algorithm used to change the second part of the message packet. 
     
     
         66 . The communication node apparatus of  claim 65  wherein the communication port is further configured to send the message packet with the third part using an algorithm different from the second part of the message packet in response to a state of a systems for the common control network being in a sensitive state. 
     
     
         67 . The communication node apparatus of  claim 59  wherein the first part is scattered over at least a portion of the second part of the message packet. 
     
     
         68 . The communication node apparatus of  claim 59  wherein the communication port is further configured to communicate a third portion of the message packet that includes semi dynamic bits. 
     
     
         69 . The communication node apparatus of  claim 68  wherein the semi dynamic bits are scattered over at least a portion of the second part of the message packet.